To answer the original question, I suggest that you approach the problem as if it was you who were trying to cache the money. This requires old maps, familiarization with the area, and identifying landmarks that they might have used for their return to recover it. I found an empty cache site, in this manner, that once held the multi-million dollar fortune of a prohibition gangster. I've noticed that many suggest that you can always find a trail of breadcrumbs leading to the treasure if you do enough research. That's not true. You may just have to apply your own intuition and do the legwork. I'm not knocking research. But, I've come to believe that you have to use your own strengths. I'm not a good researcher. In the above case, I just got out there and looked, using my common sense and intuition. Perhaps there was info that would have made my search easier. But, I didn't find it. There are clearly good researchers who post here. There are also armchair treasure hunters, who will never find anything. It would be great to find some useful info. But, it just may not exist. Just get started, and don't wait for someone here to tell you what to do or where to look. General concepts; During the revolutionary war there was much irregular activity behind the scenes, with each side doing what is could to affect the outcome. Tax collectors from each side levying the citizens to finance the war effort, with much war profiteering going on. These gangs of "tax collectors" robbed each other and attempted to bully and intimdate the citizens on the other side, who very often knew each other. These were former neighbors, who were forced to take sides once the conflict started. The battles were often fought by militia, rather than regular army forces, with the members returning to their homesteads after the fight. You can be sure that, though Bates was a captain in the colonial militia, Bates tavern held few secrets from the other side. The question was raised as to whether or not Bates was in on the robbery, if there was one. Good point. I think not. Because, his family would have had the trappings of wealth and mobility, not indicated by his family continuing to run the tavern. The transportation of such a fortune would surely have been a closely guarded secret. Would Bates have know in advance? If France sent the money, whose coin did they send? Perhaps they did not send French coin, if they wanted to conceal their fingerprints from the British. France had the resources to do so. If you focus on the details that some may emphasize, you could be putting blinders on, or even get discouraged. So, the answere is that there is no answer. We don't know the details, and they may not exist. To even find one coin would make your efforts rewarded. Get out there. After an extensive and distinguished law enforcement career, my strength is getting inside criminal minds. These would have been murders and robbers, commiting their crime behind the guise of loyalty to their cause. I'm not sure that this is real. But, I'll give you this scenario. I've estimated about a ton and a half of coin, not 13 wagon loads, though there may have been 13 supply wagons. When the coin was discovered, they would have stayed on the regular roads long enough to get away from the scene of the crime. But, not too far, lest they be spotted. Then they would have gotten off the road to bury the cache. But, not too far, for the wagons were heavy, and, then, probably out of sight from the road to avoid being spotted by a passerby, say behind a hill, around a lake, or along a stream. Thus, concealment along with the landmark to find it again. There would have been a landmark for them to find it again. They would have wanted to deny the colonials of the money, while keeping it themselves for the future. The slitting of the throats, rather than musket or sword, was to maintain silence, which means they were concerned about being spotted, and the guards were dismounted from the wagons. Probably, at the taven when the guards were liquored up, thanks to Captain Bates hospitality. The placement of the wagons, afterward, would have been to distract the inevitable search party from finding the actual location. Thus, the cache location is probably slightly farther from the tavern, than the field where the wagons were found, But, I'd guess, in the same general direction. So, view old maps to see what roads existed, side by side with new topo maps, having the details not represented on the old maps, to identify potential sites. Then, visits to the area to sort them out and prioritize your search. Start within a half mile of where the wagons were later found. At least I've tried to tell you something useful. Good luck.
something one should think of very carefully be going "public" if one should find said loot. 
